We know you’ve got a few days off over the holidays, so give us a big present and help us test! Don’t forget that jQuery 1.x supports IE 6/7/8 and jQuery 2.x does not. In other ways the two versions should echo the same feature sets, so it should be possible to switch between the two without too much trouble.

Notable changes

Asynchronous Module Definition (AMD): jQuery components are now built with AMD. jQuery has supported having the library itself loaded by an AMD loader ever since version 1.7. Now, we’re using AMD internally as well, replacing our old modular build system. If you want to know more, see the README file.

Published on npm: The 2.x branch of this beta and all our future 2.x releases will be published on npm so that you can use it with node or packages like browserify. If you want to install the beta, you can use npm install jquery@2.1.0-beta3.

Still to come: No global for the npm version: After polling potential npm/browserify users, we have decided to keep the global namespace clean and not to expose the jQuery global in these situations. Instead, you can do it yourself with window.jQuery = window.$ = require("jquery"). That ticket didn’t make it into the beta, but you should assume you’ll need to set it yourself.

Performance: Our new “lazy feature detects” reduce the startup time for the library, which is especially good for mobile devices. If you never call the API, you never even need to run that code! We also found and removed some situations where jQuery unnecessarily forced a page layout to occur.

Bug fixes: Lots and lots of bug fixes are in this release, including several to ensure the latest versions of browsers like IE11 work smoothly and eliminate console warnings in Chrome. Many fixes are shared across both versions. You can see the complete changelog below.

And then, on the roof, I heard at the ready,
The loading of code that was solid and steady.
As I drew in my head, and was turning around,
Down the chimney St. jQuery came with a bound.

“I’m needing your help,” St. jQuery exclaimed,
“If we ship code with bugs I know I’ll be flamed!”
“Just run this beta with your best sites and apps,
so we know if our changes avoided the traps.”

More rapid than eagles contributors came,
He whistled, and shouted, and thanked them by name!
“Now Timmy! now, Richard! now Micha&#322 and John!
On Oleg! On Chris! On Jakob and Hong!
To the top of the list, your reward won’t be small!
Now cache away! Cache away! Cache away all!”

He sprang to his sleigh, to his team gave a whistle,
And away they all flew like the down of a thistle.
But I heard him exclaim, as he drove out of sight,
“Happy beta to all, and to all a good-night!”